The present invention relates generally to eggs and, more particularly, to devices for injecting substances into eggs.
Injections of various substances into avian eggs have been employed to decrease post-hatch mortality rates, increase the potential growth rates or eventual size of the resulting chicken, and even to influence the gender determination of the embryo. Similarly, injections of antigens into live eggs have been employed to incubate various substances used in vaccines which have human or animal medicinal or diagnostic applications. Examples of substances that have been used for, or proposed for, in ovo injection include vaccines, antibiotics and vitamins. In addition, removal of material from avian eggs has been employed for various purposes, such as testing and vaccine harvesting. Examples of in ovo treatment substances and methods of in ovo injection are described in U.S. Pat. No. 4,458,630 to Sharma et al. and U.S. Pat. No. 5,028,421 to Fredericksen et al., the contents of which are incorporated by reference herein in their entireties.
In ovo injections of substances typically occur by piercing the egg shell to create a hole through the egg shell (e.g., using a punch or drill), extending an injection needle through the hole and into the interior of the egg (and in some cases into the avian embryo contained therein), and injecting treatment substance(s) through the needle. An example of an injection device designed to inject through the large end of an avian egg is disclosed in U.S. Pat. No. 4,681,063 to Hebrank; this device positions an egg and an injection needle in a fixed relationship to each other, and is designed for the high-speed automated injection of a plurality of eggs. Alternatively, U.S. Pat. No. 4,458,630 to Sharma et al. describes a bottom (small end) injection machine.
Injection devices conventionally utilize solenoid-driven diaphragm pumps for selectably dispensing vaccine or other substances into eggs. Unfortunately, these pumps may be costly to maintain and replace, may be difficult to clean, and may not dispense vaccines or other substances with accuracy and/or consistency. Moreover, these pumps are conventionally designed to dispense a specific volume and may not allow for different (for example greater) volumes to be dispensed. In addition, vaccine dispensing manifolds are typically required which can be complex to produce and difficult to clean.
In view of the above discussion, methods and apparatus for delivering predetermined dosages of fluids (e.g., treatment substances) to egg injection heads of an in ovo injection apparatus are provided. According to embodiments of the present invention, a method of delivering a predetermined dosage of fluid to an egg injection device (e.g., an injection head) includes drawing fluid from a fluid source into a syringe barrel via inlet tubing in fluid communication with the fluid source and with the syringe barrel, and dispensing a predetermined dosage of fluid from the syringe barrel to the egg injection device via outlet tubing in fluid communication with the egg injection device and with the syringe barrel. The outlet tubing is closed (e.g., pinched closed) during the drawing step, and the inlet tubing is closed (e.g., pinched closed) during the dispensing step.
According to embodiments of the present invention, a method of delivering a predetermined dosage of fluid into an egg includes: drawing fluid from a fluid source into a syringe barrel via inlet tubing in fluid communication with the fluid source and with the syringe barrel; inserting an injection device into an egg, wherein outlet tubing is in fluid communication with the injection device and with the syringe barrel and wherein the outlet tubing is closed (e.g., pinched closed) so as to prevent the flow of fluid therethrough; closing the inlet tubing (e.g., pinching the inlet tubing closed); opening the outlet tubing; and dispensing a predetermined dosage of fluid from the syringe barrel through the outlet tubing and into the egg via the injection device. The outlet tubing is then closed (e.g., pinched closed), the inlet tubing is opened, and the injection device is withdrawn from the egg. The inlet and outlet tubing may be opened and flushed with a sanitizing fluid.
According to embodiments of the present invention, a device for delivering predetermined dosages of fluids (e.g., treatment substances) to an egg injection head of an in ovo injection apparatus includes a syringe, compressible inlet and outlet tubing for delivering fluid to an injection head, and a flow control apparatus. The syringe includes a barrel having proximal and distal ends and inlet and outlet ports in fluid communication with the barrel and with the compressible inlet and outlet tubing, respectively. The syringe also includes a plunger that is adapted for reciprocal movement within the barrel such that fluid is drawn into the barrel through the inlet port by a proximal motion of the plunger, and such that fluid is expelled from the barrel through the outlet port by a distal motion of the plunger. The flow control apparatus is configured to pinch the outlet tubing closed during proximal motion of the plunger and to pinch the inlet tubing closed during distal motion of the plunger.
According to embodiments of the present invention, the flow control apparatus includes a first valve configured to close the outlet tubing during proximal motion of the plunger, and a second valve configured to close the inlet tubing during distal motion of the plunger. The first and second valves may be pinch valves according to embodiments of the present invention.
According to embodiments of the present invention, the flow control apparatus includes a rocker arm pivotally operable relative to the inlet and outlet tubing. The rocker arm includes opposite first and second end portions. The rocker arm first end portion is configured to pinch the inlet tubing closed during distal motion of the plunger. The rocker arm second end portion is configured to pinch the outlet tubing closed during proximal motion of the plunger.
According to embodiments of the present invention, a device for delivering predetermined dosages of fluids (e.g., treatment substances) to an egg injection head of an in ovo injection apparatus includes a frame, a syringe positioned adjacent to the frame, an elongated member mounted to the frame for reciprocating movement along a longitudinal axis thereof, and compressible inlet and outlet tubing for delivering fluid to an injection head. The syringe includes a barrel having proximal and distal ends and inlet and outlet ports in fluid communication with the barrel and with the compressible inlet and outlet tubing, respectively. The syringe also includes a plunger that is adapted for reciprocal movement within the barrel such that fluid is drawn into the barrel through the inlet port by a proximal motion of the plunger, and such that fluid is expelled from the barrel through the outlet port by a distal motion of the plunger.
The elongated member includes opposite proximal and distal ends. First and second passageways extend through an intermediate portion of the elongated member along a first direction that is substantially transverse to the elongated member longitudinal axis. Third and fourth passageways extend through the elongated member along a second direction that is substantially transverse to the elongated member longitudinal axis and to the first direction. The first and third passageways are in communication with each other, and the second and fourth passageways are in communication with each other.
The compressible inlet tubing extends through the third passageway and is connected to a fluid source at one end and to the syringe inlet port at an opposite end. The compressible outlet tubing extends through the fourth passageway and is connected to the injection head at one end and to the syringe outlet port at an opposite end. A first squeeze bar extends through the first passageway and is fixed relative to the reciprocating elongated member. A second squeeze bar extends through the second passageway and is fixed relative to the reciprocating elongated member. The first and second squeeze bars may be secured to the frame and/or to another relatively fixed structure.
The first squeeze bar is configured to pinch the compressible inlet tubing when the elongated member is moved in the distal direction. Similarly, the second squeeze bar is configured to pinch the compressible outlet tubing when the elongated member is moved in the proximal direction.
An actuator system, is configured to move the elongated member in reciprocating motion along the longitudinal axis between at least three positions. In a first position, the elongated member is moved along the longitudinal axis thereof in a proximal direction such that the compressible outlet tubing within the fourth passageway is pinched closed by the second squeeze bar so as to prevent the flow of fluid therethrough. In a second position, the elongated member is moved along the longitudinal axis thereof in a distal direction such that the compressible inlet tubing within the third passageway is pinched closed by the first squeeze bar so as to prevent the flow of fluid therethrough. In a third position, the elongated member is moved along the longitudinal axis to a position between the first and second positions such that neither the compressible inlet tubing nor the compressible outlet tubing is pinched closed by the respective squeeze bars.